Implantable medical devices (IMDs) detect and deliver therapy for a variety of medical conditions in patients. IMDs include implantable pulse generators (IPGs) or implantable cardioverter-defibrillators (ICDs) that deliver electrical stimuli to tissue of a patient. ICDs typically comprise, inter alia, a control module, a capacitor, and a battery that are housed in a hermetically sealed container. When therapy is required by a patient, the control module signals the battery to charge the capacitor, which in turn discharges electrical stimuli to tissue of a patient.
The battery includes a case, a liner, an electrode assembly, and electrolyte. The liner insulates the electrode assembly from the case. The electrode assembly includes electrodes, an anode and a cathode, with a separator therebetween. For a flat plate battery, an anode comprises a set of anode electrode plates with a set of tabs extending therefrom. The set of tabs are electrically connected. Each anode electrode plate includes a current collector with anode material disposed thereon. A cathode is similarly constructed. Electrolyte, introduced to the electrode assembly via a fill port in the case, is a medium that facilitates ionic transport and forms a conductive pathway between the anode and cathode.
Heat generated during discharge of the battery can result in high localized current densities in each current collector. It is desirable to overcome high localized current densities in current collectors.